Batch edit backgrounds - possible?

In Captivate is it possible to 'batch edit' the backgrounds without having to export them all (in one go ) and then reimport and assign them one-at-a-time to the correct slides ?

What I can do is export and edit in two steps but cannot then get them back into the project as replacements for the originals without doing each one individually.

What I am trying to achieve is to add a tint to the instruction video to make it clear to the user they are in the simulation and not the real application.

Thanks

Dave